Time and timekeeping
in the past there had been many sytems of timekeeping like the gregorian, roman, greek, egypt, maya, india etc systems. It seems to be quite a challenge to keep up whith time. On this page you will find information about calendar systems and timekeeping.
Introduction Do you know what year we live in? According to my PC it is <% =now()%>, but that is according to OUR calendar, the gregorian one. There are and have been many other calendar systems. Mostly they tell something about a special date, for example when christ was born.
Also, the Mayas in mexico had an extra month of 5 days in their holy calendar. Note that this is much later than the egyptians. There are a few possible reasons why the year was initially 360 days:
a moon-period is 27.3 days, so we can rule out the first possibility. The second possibility could be that the year really was 360 days. Geologic science have turned out that because the earth rotation around her own axis is not constant but declines with 2.3ms/day/century, we had about 3.5 mln years ago days of 19 hours! So because the slowing down of the earth (the reason for this is the drag from the oceans because the tides caused by the moon) the days were shorter in the past. Suppose there is also a similar drag caused by the planets so the movement of the earth around the sun is also slowing down? So maybe a year was indeed 360 days. The third posibillity is that the year was calculated to be 360 days. The number 360 was invented already in sumerian times, the oldest known civilization on earth. So the true origin is in the mist of ancient time, maybe in pre- diluvian (before the flood) times. See my page about numbers for details about 360 you cannot simply count the days in a year, how do you know the years end? when you dont have a device to measure time, how do you know the days are getting longer again? Until the time came when the ancients could accurately measure the length of a day, they could not know when the shortest day was. The only method to know thin i can think of, is to mark the end of the shadow of a stick, and look when the shadow gets at the most distant point (for winter), or the closest point (for summer). This is a very precice measurement. Note here that the ancients also had 24 hours in a day. When the earth slows down as it does with 2.3ms/day/century the hour in the past really was shorter! The paris based buro of time-keeping adds a leap-second once in a while to keep up with this speed-difference.
Sumerian Calendar In the sumerian era (4000-3500 BC) people thought that the year was 360 days
long. But in the egyptian time they knew there was something wrong with it, they
noticed that the year is not exactly 360 days. With their new calculations they
added 5 days. This new calendar was introduced only after the start of dynastic
rule in Egypt, i.e., after 3100 BC; according to Richard A. Parker (The
Calendars of the Ancient Egyptians) It is significant that ancient people acknowledged extremely long periods of time. The Sumerians reckoned in periods of 60 years, equal to one soss, 600 (60 X 10) years equal to one ner, and 3600 (60 X 60) years equal to one sar. (Note the sar designation, for kingly rulership.) If this scheme is carried farther a great sar of 60 X 3600 would be equal to 216,000 years. That number is exactly one-half of the Berossus sum for his king ages = 432,000 Ancient Egyptian CalendarSirius, considered by the ancient Egyptians to be the most important star in the sky, was astronomically the foundation of their entire religious system. Its celestial movements determined the Egyptian calendar...Sirius' heliacal rising (when Sirius again rose into visibility after being hidden by the Sun's light for 70 days) marked the beginning of the Egyptian year and roughly coincided with the flooding of the Nile - major events marked by feasting and celebration. The first Egyptian calendar had been
a lunar calendar, however this was later changed to a solar one with twelve
thirty day months. The year began with the heliacal rising of Sirius on or near
the Solstice. In order to have the calendar year fit the solar year, five feast
days were added to the end of the year. By creation of a 365 day year, it was still short by approximately 1/4 day, and so within four years, the calendar was one day behind the Sun. Over many years, the calendar became more and more out of synch. It was determined that it would take 1461 years to complete the solar cycle to account for the loss of about 1/4 day per year and put the calendar back in sync with the Sun, so that New Year's Day would coincide with the heliacal rising of Sirius and the Solstice. Hindu Brahma calendarIn the mythologies of the Hindus Brahma lived one hundred days and nights. Each night saw the dissolution of the world; each day saw the renewal of creation. One day and night of Brahma was equal to 1,000 periods, and each period had 12,000 divine years. Each divine year was equal to 360 human years. Therefore, one day and night of Brahma was equal to 4,320,000,000 human years. One hundred days and nights of Brahma were equal to 432 billion human years! Every period of 12,000 divine years was divided into four ages. The age of Krita was equal to 4,000 divine years with additional 400 divine years each of morning and evening twilight. The age of Krita was followed by the age of Treta with 3,000 divine years and morning and evening twilight of 300 years. This was followed by the age of Dvapara with 2,000 divine years and 200 years each of morning and evening. Lastly came the age of Kali with 1,000 years and 100 years each of morning and evening.
This one ends in 2012 AD for some reason. Also, the Mayas in mexico had an extra month of 5 days in their holy calendar.Julian Calendar, the calendar instituted by Julius Caesar as a calendar of conquest. Until the time of Julius Caesar the Roman year was organised round the phases of the moon. For many reasons this was hopelessly inaccurate so, on the advice of his astronomers, Julius instituted a calendar centred round the sun. It was decreed that one year was to consist of three hundred and sixty-five and a quarter days, divided into twelve months; the month of Quirinus was renamed 'July' to commemorate the Julian reform. Unfortunately, despite the introduction of leap years, the Julian calendar overestimated the length of the year by eleven minutes fifteen seconds, which comes to one day every on hundred and twenty-eight years. By the sixteenth century the calendar was ten days out. Gregorian calendar (Pope Gregory XII, 1582). In 1582 reforms instituted by Pope Gregory XIII lopped the eleven minutes fifteen seconds off the length of a year and deleted the spare ten days. This new Gregorian calendar was adopted throughout Catholic Europe. Protestant Europe was not going to be told what day it was by the Pope, so it kept to the old Julian calendar. This meant that London was a full ten days ahead of Paris. The English also kept the 25th of March as New Year's Day rather than the 1st of January. By the time England came round to adopting the Gregorian calendar, in the middle of the eighteenth century, England was eleven days ahead of the Continent. A Calendar Act was passed in 1751 which stated that in order to bring England into line, the day following the 2nd of September 1752 was to be called the 14th, rather than the 3rd of September. Unfortunately, many people were not able to understand this simple manoeuvre and thought that the government had stolen eleven days of their lives. In some parts there were riots and shouts of 'give us back our eleven days!' Before the calendar was reformed, England celebrated Christmas on the equivalent of the 6th of January by our modern, Gregorian reckoning. That is why in some parts of Great Britain people still call the 6th of January, Old Christmas Day Although the system was declared in 1582, it took many years for adoption. Germany and the Netherlands agreed to adopt the Gregorian calendar in 1698; Russia only accepted it after the revolution of 1918, and Greece waited until 1923 to follow suit. And currently many Orthodox churches still follow the Julian calendar, which now lags 13 days behind the Gregorian. this system is still in official use in most western countries. The Gregorian calendar year differs from the solar year by only 26 seconds. This is accurate enough for most people, since this only adds up to one day's difference every 3,323 years. Despite its widespread use, the Gregorian calendar has a number of weaknesses. It cannot be divided into equal halves or quarters; the number of days per month is haphazard; and months or even years may begin on any day of the week. Holidays pegged to specific dates may also fall on any day of the week, and vanishingly few Americans can predict when Thanksgiving will occur next year. Since Gregory XIII, many other proposals for calendar reform have been made. In the 1840s, philosopher Auguste Comte suggested that the 365th day of each year be a holiday not assigned a day of the week. The generic "Year Day" would allow January 1 to fall on a Sunday every year. Needless to say, this clever solution was not widely embraced. The French Revolution calendar The French Revolution also saw an attempt at the introduction of a new calendar. On October 5, 1793, the revolutionary convention decreed that the year (starting on September 22, 1792—the autumnal equinox, and the day after the proclamation of the new republic) would be divided into 12 months of 30 days, named after corresponding seasonal phenomena (e.g. seed, blossom, harvest). The remaining five days of the year, called sans-culottides, were feast days. In leap years, the extra day, Revolution Day, was to be added to the end of the year. The Revolutionary calendar had no week; each month was divided into three decades, with every tenth day to be a day of rest. This straightforward calendar, however, perished with the Republic. The Islamic (Hijri) Calendar The Islamic calendar is based on the lunar year of 354 days. The number of days each month is adjusted according to the lunar cycle, beginning about two days after the new moon. The months drift backward over the seasons, beginning again on the same day every 32 1/2 years. The Islamic year begins on the first day of Muharram, and is counted from the year of the Hegira (anno Hegirae)—the year in which Muhammad emigrated from Mecca to Medina (A.D. 622). The year 2004 translates to A.H. 1424–1425. Julian Day calendar Julian Day calendar, system of astronomical dating that allows the difference between two dates to be calculated more easily than conventional civil calendars with their uneven months. It was devised by Joseph Scaliger in 1582 and named in honor of his father, Julius Caesar Scaliger. The Julian period. of 7,980 years is a product of the solar cycle, the lunar cycle, and the Roman indiction cycle and begins on Jan. 1, 4713 B.C., that being the nearest past year in which the three cycles coincided. Dates are numbered consecutively from that day, regardless of the various changes made in civil calendars based on changing definitions of the year. The Julian Day number for Dec. 31, 1999, is 2,451,544; for Jan. 1, 2000, is 2,451,545; for Jan. 2, 2000, is 2,451,546; and so on. The Julian Day is from noon, universal time, on the given date to noon of the following date. Precession I also want to put some words on Precession. Precession is the 'wobble' the earth makes while rotating. The duration of the wobble is supposed to be about 25920 years. But that is only an approximation. According to NASA the real figure varies by time. It is said that the ancients had knowledge of precession. In deep discussions about the subject i found that the ancients could know about precession because a degree of shift of the stars is visible in 72 years, and therefore it was possible to notice this shift for priest who presumably made exact measures. So yes, they had knowledge of precession. But it is possible, that because of the number 6 is considered holy, and 12 x 6 = 72 the precession circle was assumed to be (72 x 360=) 25920 years and not measured? Maybe the ancients had something like Einsteins' Unified Theory and therefore calculated the precession cycle to be 25920 years. How exact is this figure? Because when this figure turns out to be not very
exact because of variations in the speed of the wobble, then the above stated
could be right. Then it was maybe just an assumption the ancients made, like a
theory which was not proven. There are many more examples of an assumed number
in scientific theories around the world. See for further comments on 25920 this site. Internet Timetoday there is also something called internet time, see this Every day is a special one, see the Ecyclopedia of days UPDATE - Someone discovered a relationship between movement of planets and the fibonacci sequence Click here to perform a search in the database on calendar cycles | |||||||||||||||